Planning Your Single Storey Extension
A single storey extension is one of the most popular home improvement projects for Liverpool homeowners. It adds valuable living space, increases property value, and can be completed relatively quickly compared to larger projects. However, successful planning requires understanding costs, timescales, building regulations, and permission requirements before you begin.
Omnis Developments specialises in single storey extensions and has helped hundreds of customers navigate the planning process. This guide walks you through everything you need to know before committing to your project.
Understanding Single Storey Extension Costs
Single storey extension costs vary significantly based on size, specification, and location within your home. A basic single storey extension of 20 square metres typically costs between £20,000 and £35,000. Larger extensions, premium finishes, and complex structural requirements push costs higher.
Cost factors include structural works, foundation depth, building material quality, electrical and plumbing installation, window and door specifications, and finishing standards. Getting accurate cost information requires a professional assessment of your specific property and requirements. Omnis Developments provides detailed cost breakdowns so you understand exactly where money is being spent.
Building Regulations and Compliance
All single storey extensions must comply with Building Regulations, whether or not they require planning permission. Building Regulations cover structural integrity, foundations, insulation standards, electrical safety, plumbing, and fire safety. Non-compliance creates safety risks and causes problems when selling the property.
Omnis Developments manages all Building Regulations compliance. We obtain necessary approvals, arrange inspections at each construction stage, and provide Building Regulations completion certificates. This protects your investment and ensures your extension is safe and legally compliant.
Planning Permission vs Permitted Development
Many single storey extensions qualify for Permitted Development rights, meaning you can build without planning permission. Permitted Development rules have specific limits: your extension must not exceed 4 metres in height, extend beyond the rear building line by more than 3 metres, or cover more than 50 per cent of your garden. Extensions to the front of terraced properties rarely qualify.
If your extension exceeds these limits or the permitted development rules do not apply, you need planning permission. The planning process takes 8-12 weeks and includes a public consultation period. Omnis Developments guides you through permission requirements and handles all documentation if needed.
Design and Space Optimisation
Single storey extensions offer huge flexibility in design. Whether you want a new kitchen-diner, expanded living room, home office, or bedroom, extension design should reflect your lifestyle and maximise the benefit of your new space. Poor design leads to wasted space and disappointing results.
Omnis Developments works with you to design extensions that perfectly suit your needs. We consider natural light, flow to existing rooms, insulation and heating efficiency, and how the extension connects with your home’s existing style. The result is a space that feels natural and adds genuine value.
Timescales: From Planning to Completion
Single storey extension timescales depend on whether planning permission is needed. Permitted Development extensions typically take 3-5 months from starting work to completion. This includes foundation work, structural construction, roofing, installation of services, and final finishing.
If planning permission is required, add 8-12 weeks before construction begins. Omnis Developments provides realistic timescales based on your specific project and keeps you updated throughout. We work efficiently without cutting corners, ensuring quality results delivered on schedule.
Frequently Asked Questions
Do all single storey extensions need planning permission?
No. Many qualify for Permitted Development rights and can be built without planning permission. However, you must comply with Building Regulations regardless. Omnis Developments assesses whether your extension needs permission during the initial consultation.
Can I extend the full width of my property?
Yes, full-width extensions are common and often make the most efficient use of space. Building Regulations and planning permission (if required) ensure safety and do not prevent full-width designs.
How much value does a single storey extension add?
A well-designed, high-quality single storey extension typically adds 10-15 per cent to property value. The investment often recoup costs through increased home value and enhanced living quality.